Lawyers acting for Optus in the Supreme Court of Victoria today will likely argue that Telstra is acting hypocritical in calling an Optus ad for mobile coverage misleading and deceptive, when Telstra's own ad has similar imagery.

On Friday, Telstra took Optus to court, seeking to have an ad for its mobile network coverage pulled off the air. The ad that has aired since January 29 places the two population coverage percentages of Telstra and Optus in a map of Australia.

Telstra has claimed that this ad is misleading because it infers that Optus' geographical network coverage is approximately 1 percent smaller than Telstra's, when Telstra's network covers 2.3 million square kilometres of Australia and Optus' covers about 1 million square kilometres.

But in an ad released in December explaining Telstra's 4G network, and highlighting its availability across Australia, Telstra also used a map of Australia, similar to that used by Optus. Although no percentages are announced in the ad, the map of Australia does appear in the ad in relation to the network coverage.

Telstra's 4G ad.
Image: Screenshot by Josh Taylor/ZDNet

Optus' ad.
Image: Screenshot by Josh Taylor/ZDNet

Despite the similarity in the ads, a spokesperson for Telstra denied that the ads are both misleading.

"The two ads are very different. Unlike Optus, when we show the map of Australia, we are making a geographic coverage claim — which is that Telstra has four times the 4G coverage area of other networks. This is true," the spokesperson said.

"We also make a separate population coverage claim — which is that 4G covers 85 percent of Australia's population. This is also true, and we make no comparison to Optus' population coverage."

The spokesperson said that Optus used a map only when talking about population coverage, and not geographical coverage.

"The difference in geographic coverage is literally many hundreds of thousands of square kilometres. Again, we call on Optus to be clear with Australians about the extent of their mobile network coverage."

Telstra had sought an injunction to pull Optus' ad off the air on Friday, pending a hearing on Wednesday. At the hearing, however, ZDNet understands that Optus agreed to pull the YouTube clip of the ad without admitting guilt, but was allowed to keep airing the ad on TV because air time had already been booked.